Olefin cross metathesis is an established catalytic process for the breaking and formation of carbon-carbon bonds between olefinic groups of two separate molecules. In a simple system using two different olefin starting materials, six products are formed:

Metathesis chemistry is established and used industrially in the petrochemical industry. Catalysts for these processes include, for example, Grubbs catalysts. Recently, it has been shown that a subset of the Grubbs catalysts can be useful for transforming natural oils, such as those from vegetable or animal sources, to higher value derivatives, such as terminal olefins and bi-functional molecules including diacids, diesters, and omega unsaturated acids and esters. A drawback to this approach, however, is the complexity of the mixture of products that result from the reaction, and the poor yield of the desired product, resulting in challenging recovery and isolation processes, and ultimately more expensive products.
The source of the complexity arises from the natural complexity of natural oils. Natural oils are predominantly composed of a diverse mixture of triacylglycerides (TAGs). TAGs are composed of three fatty acids each esterified to one of the three hydroxyl groups of a glycerol molecule. In each TAG, each of the three fatty acids can vary in structure, having variable chain lengths and level and location of unsaturation. Most common vegetable oils have chain lengths in the C12-C22 range, and each fatty acid moiety may contain three or more olefinic bonds. As each olefinic bond is reactive with the other olefinic bonds in the mixture, metathesis produces a tremendous number of products when natural oils are used as a starting material. Indeed, there is an exponential increase in the number of products with each additional olefin in the mixture.
Thus, a less complex and more specific set of olefinic reactants would result in a less diverse more specific set of products, and would be a much more cost effective way to make a particular desired olefin.